What is cryptography ? 

      Cryptography is a software technique intended to protect sensitive information by encoding it in a way that makes it accessible only to those intended to decode and process it. It has the meaning of crypt-hidden and graphy-writing hidden.

Techniques used –

Among the methods of cryptography, encryption involves the transformation of plaintext into ciphertext. In addition to encryption, cryptography includes the process of decryption, which involves converting ciphertext back into plaintext.

Why cryptography ?

    By using cryptography, you are ensuring:

          1. Authentication – establishing that the sender and receiver are whom they claim.

          2. Confidentiality – protecting the information from being disclosed to unauthorized parties.

          3. Non-repudiation – this means the sender can’t deny a given act after a message has been sent.

          4.  Integrity – unauthorized changes to data cannot be made during transmission or processing.

Types of Cryptography :

1. Symmetric Key Cryptography :
    A cryptographic algorithm that uses the same key for both encryption of plaintext and decryption of ciphertext for electronic transmission of information. It is fast and requires little computer processing power.

2. Hash Functions :
     A hash function is a non-key algorithm that converts data from arbitrary length into a fixed length using a technique designed to digest the data. This digested data is much smaller than the original plaintext, making it difficult to recover the original text.

3. Asymmetric Key Cryptography :
    Unlike symmetric cryptography, this system encrypts with a public key and decrypts with a private key; one key is used for encrypting and one for decrypting. Public keys have the function of encrypting data, but only the intended recipient can decrypt it, since private key decryption is only possible.

Applications of cryptography

  • Authentication/Digital Signatures.
  • Time Stamping.
  • Electronic Money.
  • Secure Network Communications.
  • Anonymous Remailers.
  • Disk Encryption.